Some mobile information devices can capture images. Such mobile information devices may comprise image pickup devices, such as Complementary Metal Oxide Semiconductor (CMOS) sensors, Charge Coupled Devices (CCD), and the like as an image pickup device. In the image pickup device, when three primary colors such as red (R), green (G), and blue (B) are obtained, light is transmitted through color separation filters having optical bands corresponding to R, G, and B. The color separation filters comprise a dye or a pigment, and a target color is transmitted through a corresponding color separation filter. However, the color separation filters transmit light in an infrared region and at a constant rate while transmitting the target color.
Human visual sensory systems have a sensitivity characteristic to colors of about 380 nm to about 780 nm, which is called a visible region. A near-infrared region has a wavelength of about 780 nm to about 2500 nm, and an infrared region has a wavelength of about 2500 nm or more. Although rays of light may not be directly seen by a naked eye, the rays of light can be seen by a monitor of a digital camera or a video camera comprising an image pickup device. In order to match a sensitivity characteristic of the image pickup device with that of human eyes, sometimes an image pickup device comprises an Infrared Ray Cut Filter (IRCF). The IRCF generally cuts the rays in the infrared and near-infrared regions.
The IRCF may reduce color distortion by blocking absorption of the infrared light from the image pickup device. Blocking absorption of the infrared light from the image pickup device allows the image pickup device to optimize reception for visible light. However, during low light conditions lack of energy from the infrared light may reduce total light energy received by the image pickup device below a useful threshold for image reception. Therefore, there is a need for improving color reproducibility of an image pickup device during high light level and low light level conditions.